In 2003, there were intense solar storms at the end of October and the beginning of November that wreaked havoc on satellites in orbit, blew transformers in northern Europe, and even caused airlines to reroute flights to avoid possible damage. Space weather had an even greater impact in 1989, when a geomagnetic storm knocked out power to most of Quebec for over nine hours. Clearly, a stormy day on the Sun can have far-ranging consequences.

The capacity to cause disruption to the electrical grid probably has the greatest societal and economic impact; although not caused by space weather, the blackout that affected the northeastern US and Canada in 2003 had an economic impact in the range of $5 billion-10 billion. However, like category 5 hurricanes, such events are thankfully relatively rare.

Greater societal impacts beyond those caused by a regional blackout were identified as a function of the greater connectedness of modern life; with so many sectors of the economy dependent upon others, one or two points of failure might have a cascading effect (water outages, transportation breakdowns and so on).

The space industry is at greater risk from space weather, since geomagnetic storms can affect satellite launches as well as spacecraft in orbit. The 2003 storm resulted in the loss of the ADEOS-2 spacecraft at a cost of more than $600 million, and the FAA's recently implemented GPS-based Wide Area Augmentation System (a navigation aid for flights over the continental US) was out of action for more than a day. There are also costs imposed by delays to launches due to adverse space weather events.

Although there's no way for us to stop the solar weather, we can at least keep an eye on it, and this task falls mainly to NOAA's Space Weather Prediction Center and the US Air Force's Weather Center. Between them, they use a variety of space- and Earth-based sensors to gather data for models that currently allow for moderately accurate predictions of severe space weather events over the long term, long term being defined as 1-3 days. However, the report points out the importance of placing a monitoring satellite at the L1 Lagrange point between the Sun and Earth, due to the fact that the current solar wind monitor, ACE, is well beyond its planned lifespan.